Disclosed herein is a side airbag apparatus that relieve impact from side bodies of motor vehicles, and more specifically, a side airbag apparatus installed between the vehicle body and the rear seat.
Conventionally, some side airbag apparatuses, which are installed between the vehicle body door and the rear seat in the width direction of the vehicle body, are known to include an inflator for injecting gas into an airbag, a box-shaped storage case for storing the airbag and the inflator, and a resin base cover for covering the storage case from the front side of the vehicle body (see, for example, Japanese Unexamined Patent Application Publications No. 2006-88850 A and No. H11-91487).
In a side airbag apparatus as described in JP-A-No. 2006-88850, when the airbag stored in the storage case is expanded by the inflator, the airbag breaks a thin part of the base cover located on the front side of the vehicle body, and then expands and deploys itself.
Specifically, in the event of an impact above a predetermined level from the side body of the vehicle, an impact sensor (not shown) senses the impact, and a power for ignition is supplied to the inflator, which then causes the airbag to expand and deploy beside an occupant.
In a side airbag apparatus for side collision as described in JP-A-No. H11-91487, an airbag module is mounted beside the rear seat and stores therein an airbag and an inflator. A cushion pad is installed at the front surface of the airbag module, and covered with a surface cover.
A stay cloth is attached to a part of the back side of the surface cover corresponding to the exterior side of the vehicle body such that the expanding directions of the airbag will be concentrated on a cleavage part of the surface cover.
With the structure described above, the airbag expands and deploys toward the cleavage part of the surface cover located on the front side of the vehicle body.
When the inflator operates to expand and deploy the airbag, a gas pressure from the inflator expanding the airbag is significantly applied to the storage case. This results in deformation of the storage case, which might adversely affect the expanding direction of the airbag.
However, the storage cases of the side airbag apparatus disclosed in JP-A-No. 2006-88850 and No. H11-91487 are not designed taking into consideration any means for reducing the gas pressure applied to the storage case when the airbag is expanded and deployed.
In particular, in the above related art, the storage case of the side airbag apparatus is made of metal in order to improve its strength. However, to achieve the weight reduction, the storage case material is changed to a resin. Even when the material for the storage case is changed to the resin, a technique is still required that can suppress the deformation of the storage case when the airbag expands and deploys itself.
In the side airbag apparatuses disclosed in JP-A-No. 2006-88850 and No. H11-91487, a stay cloth is attached to guide the expanding and deploying direction of the airbag. However, to make the expanding direction of the airbag more stable, it is still required to supplementarily guide the expanding direction of the airbag using an existing component.